<template>

    <div class="app-container">

        <h2 style="text-align: center;">发布新课程</h2>

        <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
            <el-step title="填写课程基本信息" />
            <el-step title="创建课程大纲" />
            <el-step title="提交审核" />
        </el-steps>

        <el-form label-width="120px">

            <el-form-item label="课程标题">
                <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写" />
            </el-form-item>

            <!-- 所属分类：级联下拉列表 -->
            <!-- 一级分类 -->
            <el-form-item label="课程类别">
                <el-select @change="subjectLevelOneChanged" v-model="courseInfo.subjectParentId" placeholder="请选择">
                    <el-option v-for="subject in subjectNestedList" :key="subject.id" :label="subject.title"
                        :value="subject.id" />
                </el-select>
                <!-- 二级分类 -->
                <el-select v-model="courseInfo.subjectId" placeholder="请选择">
                    <el-option v-for="subSubject in subSubjectList" :key="subSubject.value" :label="subSubject.title"
                        :value="subSubject.id" />
                </el-select>
            </el-form-item>

            <!-- 课程讲师 TODO -->
            <!-- 课程讲师 -->
            <el-form-item label="课程讲师">
                <el-select v-model="courseInfo.teacherId" placeholder="请选择">
                    <el-option v-for="teacher in teacherList" :key="teacher.id" :label="teacher.name"
                        :value="teacher.id" />
                </el-select>
            </el-form-item>

            <el-form-item label="总课时">
                <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right"
                    placeholder="请填写课程的总课时数" />
            </el-form-item>

            <!-- 课程简介 TODO -->
            <!-- 课程简介-->
            <el-form-item label="课程简介">
                <tinymce :height="300" v-model="courseInfo.description" />
            </el-form-item>
            <!-- 课程封面 TODO -->
            <!-- 课程封面-->
            <el-form-item label="课程封面">
                <el-upload :show-file-list="false" :on-success="handleAvatarSuccess" :before-upload="beforeAvatarUpload"
                    :action="BASE_API+'/oss/file/uploadImg'" class="avatar-uploader">
                    <img :src="courseInfo.cover" height="200px">
                </el-upload>
            </el-form-item>

            <el-form-item label="课程价格">
                <el-input-number :min="0" v-model="courseInfo.price" controls-position="right"
                    placeholder="免费课程请设置为0元" /> 元
            </el-form-item>

            <el-form-item>
                <el-button :disabled="saveBtnDisabled" type="primary" @click="next">保存并下一步</el-button>
            </el-form-item>
        </el-form>
    </div>
</template>
<script>
import course from '@/api/edu/course'
import subject from '@/api/edu/subject'
import teacher from '@/api/edu/teacher'
import Tinymce from '@/components/Tinymce'

const defaultForm = {
    title: '',
    subjectId: '',
    subjectParentId: '',
    teacherId: '',
    lessonNum: 0,
    description: '',
    cover: '',
    price: 0,
    cover: 'http://localhost:9001/img/2022/09/26/a966c537055549d18587d3852d0a207b.jpg'
}

export default {
    components: { Tinymce },
    data() {
        return {
            courseInfo: defaultForm,
            saveBtnDisabled: false, // 保存按钮是否禁用
            subjectNestedList: [],  //一级分类列表
            subSubjectList: [],  //二级分类列表
            teacherList: [],
            BASE_API: process.env.BASE_API // 接口API地址
        }
    },

    watch: {
        $route(to, from) {
            console.log('watch $route')
            this.init()
        }
    },

    created() {
        this.init()
        this.initSubjectList()
        this.initTeacherList()
    },

    methods: {

        init() {
            if (this.$route.params && this.$route.params.id) {
                const id = this.$route.params.id
                // 数据回显
                this.fetchCourseInfoById(id)
            } else {
                this.courseInfo = { ...defaultForm }
                // 初始化分类列表
                this.initSubjectList()
                // 获取讲师列表
                this.initTeacherList()
            }
        },

        next() {
            this.saveBtnDisabled = true
            if (!this.courseInfo.id) {
                this.saveData()
            } else {
                this.updateData()
            }
        },
        
        // 保存
        saveData() {
            
// 开发课程大纲页面用 直接跳不走保存 开发完后要关闭
            this.$router.push({ path: '/edu/course/chapter/14' })


            // course.saveCourseInfo(this.courseInfo).then(response => {
            //     this.$message({
            //         type: 'success',
            //         message: '保存成功!'
            //     })
            //     return response// 将响应结果传递给下一个then
            // }).then(response => {
            //     this.$router.push({ path: '/edu/course/chapter/' + response.data.courseId })
            // }).catch((response) => {
            //     this.$message({
            //         type: 'error',
            //         message: response.message
            //     })
            // })
        },

        // 加载一二级课程分类
        initSubjectList() {
            subject.getSubjectList().then(response => {
                this.subjectNestedList = response.data.items
            })
        },
        // 点击的value即是一级分类的id
        subjectLevelOneChanged(value) {
            // 取出每一个一级分类里面的二级分类集合
            // 用js6要重新编译一下才能使用
            for (let i = 0; i < this.subjectNestedList.length; i++) {
                if (this.subjectNestedList[i].id === value) {
                    this.subSubjectList = this.subjectNestedList[i].children
                    // 每次重新加载都会叠加，所以清空一下
                    this.courseInfo.subjectId = ''
                }
            }
        },
        initTeacherList() {
            teacher.getList().then(response => {
                this.teacherList = response.data.items
            })
        },
        handleAvatarSuccess(res, file) {
            // console.log(URL.createObjectURL(file.raw))// base64编码
            this.courseInfo.cover = res.data.url
            this.$message({
                type: 'success',
                message: '上传封面成功!'
            })
        },
        // 判断图片是否符合要求
        beforeAvatarUpload(file) {
            // const isJPG = file.type === 'image/jpeg'
            const isLt2M = file.size / 1024 / 1024 < 2
            // if (!isJPG) {
            //     this.$message.error('上传头像图片只能是 JPG 格式!')
            // }
            if (!isLt2M) {
                this.$message.error('上传头像图片大小不能超过 2MB!')
            }
            // return isJPG && isLt2M
            return isLt2M
        },
        //数据回显
        fetchCourseInfoById(id) {
            course.getCourseInfoById(id).then(response => {
                this.courseInfo = response.data.item
                // 数据回显时加载课程分类
                subject.getSubjectList().then(response => {
                    this.subjectNestedList = response.data.items
                    for (let i = 0; i < this.subjectNestedList.length; i++) {
                        if (this.subjectNestedList[i].id === this.courseInfo.subjectParentId) {
                            this.subSubjectList = this.subjectNestedList[i].children
                        }
                    }
                })
                this.initTeacherList()
            }).catch((response) => {
                this.$message({
                    type: 'error',
                    message: '数据回显失败'
                })
            })
        },

        //更新课程
        updateData() {
// 开发时用
            this.$router.push({ path: '/edu/course/chapter/14' })

            // this.saveBtnDisabled = true
            // course.updateCourseInfoById(this.courseInfo).then(response => {
            //     this.$message({
            //         type: 'success',
            //         message: '修改成功!'
            //     })
            //     return response// 将响应结果传递给下一个then
            // }).then(response => {
            //     this.$router.push({ path: '/edu/course/chapter/' + response.data.courseId })
            // }).catch((response) => {
            //     // console.log(response)
            //     this.$message({
            //         type: 'error',
            //         message: '保存失败'
            //     })
            // })
        }

    }
}
</script>
<style scoped>
.tinymce-container {
    line-height: 29px;
}
</style>